The characterizing feature of the sub-combat unit described in the above referenced patent is that it is provided with a pivotally disposed target identification and triggering sensor and with one or more similarly outwardly pivotal aerodynamic surfaces. Together, the sensors and the aerodynamic surfaces provide, in their flip-out positions, the sub-combat unit with a suitably balanced retarding area which imparts to the unit the predetermined fall speed and rotation which make it possible for the sensors to scan the relevant target area for targets to be combatted.
Publications SE-A0-8903473-0 corresponding to U.S. Pat. No. 5,063,849 to Axinger and SE-A0-9001227-9 corresponding to U.S. Pat. No. 5,155,294 to Vesa further describe variations of flip-out aerodynamic surfaces intended for sub-combat units of the type contemplated here. The aerodynamic surfaces may also consist of parachutes.
As will be apparent from the above disclosure and in greater detail from the above-mentioned references, the sub-combat units are provided with a plurality of flip-out parts which, during the launching process from the carrier or vehicle body, must be protected from damage. At the same time, the pre-planned scanning of the target area requires that the flip-out of these parts take place exactly as pre-planned.
A further problem which must be solved is that, since each carrier body contains several sub-combat units, systems must be integrated in the design which give the different sub-combat units a desired spread and ensure that launched parts do not collide with one another in the air after launching.
Launching of the sub-combat units from the carrier body is most simply put into effect using a powder charge which, rearwardly in the flight direction of the carrier body, forces out all sub-combat units as one single unit. This launching thus implies a certain desirable simultaneous retardation of the movement of the sub-combat units in the flight direction, but this necessitates that the more sensitive parts of the sub-combat units must be protected from damage. Moreover, the different sub-combat units must thus be separated before their aerodynamic surfaces and sensors can be flipped out.
The separation between the different sub-combat units can be effected in that these are retarded to different degrees after being launched so that the sub-combat unit which was originally placed most forwardly in the carrier body is retarded least. The retardation is progressively increased on those sub-combat units which were placed further rearwardly in the carrier body.
Once the desired retardation has taken place, the sub-combat units must be released from these specific retarder devices before carrier surfaces and sensors can be flipped out. If the carrier body or vehicle has been rotation-stabilized, rotation brakes may also be included. The problem inherent in protecting the sub-combat units during the launching phase and the requirement of having access, during the specific separation phase, to retarder devices connected to the sub-combat units is solved by surrounding the sub-combat units with specific protective canisters. The retarder devices and possibly rotation brakes may be secured to the protective canister. Also, the sub-combat units are, in their turn, discharged from the protective canister once the desired retardation in respect of both rotation and flight speed has been completed.
The protective canister can then simultaneously be utilized for holding the aerodynamic surfaces and the sensors in the inwardly folded state. This implies that the aerodynamic surfaces and the sensors will be flipped out as soon as the sub-combat unit has left its protective canister. Discharge of the sub-combat unit from the protective canister must, however, be affected in such a manner that no parts are damaged. At the same time, it must be ensured that the now activated sub-combat unit runs no risk of colliding with its own former protective canister or corresponding canisters from other sub-combat units.
The present invention therefore relates to a method and an apparatus intended to solve the above-described specific problems. Accordingly, the present invention entails a method of discharging sub-combat units from their protective canisters without sensors and aerodynamic surfaces being damaged. At the same time, the mutually separated canisters and sub-combat units are given different fall trajectories and fall speeds. The different trajectories and speeds eliminate the risk of collision between the sub-combat units and the canisters. The present invention also includes an apparatus designed in accordance with the above-described method.
According to the present invention, the sub-combat unit is designed in accordance with the above-disclosed general guidelines. Thus upon departed from the vehicle or carrier body enclosed in its protective canister the sub-combat unit is in turn discharged out of the protective canister by a driving sabot or ram disposed between the bottom of the canister and the sub-combat unit and displaceable towards the open end of the canister. Behind the sabot or ram, an elevated gas pressure is generated by combustion of a gas-generating pyrotechnical charge which is initiated at the point in time of discharge of the sub-combat unit. According to the present invention, the protective canister must further be provided with arrest means which rapidly retard the driving sabot as soon as the sabot has imparted the desired discharged velocity to the sub-combat unit, so that the driving sabot does not accompany the sub-combat unit in its new trajectory. The arrest or braking means suitably consist of initially folded brake bands which are stretched on displacement of the driving sabot when the brake bands are fully stretched, they impart to the now empty protective canister a tumbling motion. According to one development of the present invention, the jerk generated on activation of the arrest means can then be utilized to cause the protective canister to divide into several parts. In a preferred embodiment, the stretching of the brake bands causes a division of the protective canister. The division of the canister further ensures that the sub-combat unit and canister parts achieve different fall speeds. This division can be effected in that the protective canister is made from several parts which are joined together in such a manner that there are natural indications of fracture between the parts.